1. Field of Invention
The invention relates to a cartridge that is exchangeably mounted on image forming apparatuses, such as printers, facsimile machines, and copiers and that fills thereinto a consumable such as toner and ink.
2. Description of Related Art
In recent years, a cartridge filled with toner as a developing medium has been used for printers, facsimile machines, and copiers. A certain amount of toner is filled into the cartridge at the time of production. The cartridge is exchangeably set in, for example, a printer. As the toner in the cartridge is used and the remaining amount of the toner is reduced, the printing quality begins to fade. The cartridge thus needs to be replaced. At this time, the cartridge may also be replenished with the toner so that the cartridge can be reused.
A method for reusing a cartridge is disclosed in, for example, paragraphs 0029 to 0031, as well as FIG. 4 of Japanese Laid-Open Patent Publication No. 2001-122361. First, a toner filling port is formed in a part of a top of the used cartridge using a tool such as a drill and a driver. Then, toner is filled through the toner filling port into the cartridge. The toner filling port is then sealed with tape. Thus, reuse of the cartridge leads to cost reductions, as well as resource savings.
The cartridge into which the toner is filled is provided with an agitator that agitates the toner in the cartridge. The agitator is rotatably disposed in the cartridge with a shaft of the agitator supported in a case of the cartridge. For example, U.S. Pat. No. 5,884,130 discloses a structure that supports a shaft of an agitator using bearings protruding from a case.
As shown in FIG. 25, a substantially V-shaped groove 202 is formed on an inner wall 201 of a case 207. With an agitator shaft 204 disposed in a deepest portion 203 of the groove 202, the groove 202 fits therein a substantially inverted trapezoidal side plate 205 provided with an upper cover 206, which is separately provided from the case 207. The shaft 204 is fixedly sandwiched between a bottom surface of the deepest portion 203 and a lower end of the side plate 205.